package cn.tedu.v6;

import java.io.*;
import java.net.BindException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.*;

/**
 * Version 6 在线用户列表
 */
public class Server {
    private ServerSocket serverSocket;
    private static final Integer PORT=4545;
    private List<PrintWriter> allOut=new ArrayList<>();
    //1.私有化集合保存所有用户名---onlineUsers
    private List<String> onlineUsers=new ArrayList<>();
    private Map<String,String> userDataBase;


    public Server() {
        try {
            serverSocket = new ServerSocket(PORT);
            userDataBase=new HashMap<>();
            userDataBase.put("1","1");
            userDataBase.put("2","654321");
        } catch (BindException e) {
            System.out.println("端口号重复申请，建议换个端口号");
        } catch (IOException e) {
            System.out.println("申请端口号失败......");
        }
    }

    public void start() {
        try {
            while (true) {
                System.out.println("------等待客户端链接------");
                Socket socket = serverSocket.accept();

                new Thread(new ClientHandler(socket)).start();
            }
        } catch (IOException e) {
            System.out.println("服务器端通讯断开了");
        } finally {
            if(serverSocket!=null&&!serverSocket.isClosed()){
                try {
                    serverSocket.close();
                } catch (IOException e) {
                    System.out.println("服务器关闭失败");
                }
            }

        }

    }


    public static void main(String[] args) {
        new Server().start();
    }


    private synchronized void broadcastMessage(String message){

        for(PrintWriter pw: allOut){
            pw.println("消息广播："+message);
            pw.println("请输入消息(输入 exit 退出)：");
        }

    }
    //2.封装方法：同步转发给所有客户端消息：“在线用户：”+onlineUsers
    //updateOnlineUsers  更新在线人数的方法：“在线用户：”+onlineUsers
    //字符串：String userList=“在线用户：”+String.join("、",onlineUsers)
    private void updateOnlineUsers(){
        String userList="在线用户："+String.join("、",onlineUsers);
    }

    private class ClientHandler implements Runnable {
        private Socket socket;
        private String ip;
        private BufferedReader br;
        private PrintWriter pw;
        private String username;
        private String password;

        public ClientHandler(Socket s){
            this.socket=s;
            ip=socket.getInetAddress().getHostAddress();
            try {
                br = new BufferedReader(new InputStreamReader(socket.getInputStream(), "UTF8"));

                pw=new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream(),"UTF8")),true);

                synchronized (allOut) {
                    allOut.add(pw);
                }

            } catch (IOException e) {
                System.out.println("客户端断开通讯~~");
            }

        }


        private boolean Login(String user,String pass){
            return userDataBase.containsKey(user)&&userDataBase.get(user).equals(pass);
        }

        private void handlerChat(){
            new Thread(()->{
                try {
                    String message;
                    while((message=br.readLine())!=null){
                        System.out.println(ip+"客户端说："+message);
                        System.out.println("服务器请输入：");

                        broadcastMessage(message);
                    }
                } catch (IOException e) {
                    System.out.println("客户端读入失败！");
                }
            }).start();


            Scanner input=new Scanner(System.in);

            while (true) {
                System.out.println("服务器请输入：");
                String say=input.nextLine();
                pw.println("服务器端说："+say);
            }
        }



        public void run() {
            try {
                pw.println("请输入用户名：");
                username=br.readLine();

                pw.println("请输入密码：");
                password=br.readLine();

                if(Login(username,password)){
                    pw.println("登录成功，欢迎进入聊天室~");
                    //3.所有用户添加至集合中【同步】
                    onlineUsers.add(username);
                    updateOnlineUsers();

                    handlerChat();
                }else{
                    pw.println("登录失败，用户名或者密码错误！");
                    socket.close();
                }


            } catch (NullPointerException e) {
                System.out.println("IO流传入对象"+"有对象为null，立马核对，" + "建议：查看try块中对象可能赋值为null");
            } catch (IOException e){
                System.out.println("服务器断开链接");
            }finally {
                //4.客户端断开链接，移除当前集合【同步】
                onlineUsers.remove(username);
                updateOnlineUsers();

                synchronized (allOut) {
                    allOut.remove(pw);
                }

                if(br!=null)
                    try {
                        br.close();
                    } catch (IOException e) {
                        System.out.println("通讯关闭失败~~");
                    }

                if(pw!=null) pw.close();

                if (socket != null&&!socket.isClosed())
                    try {
                        socket.close();
                    } catch (IOException e) {
                        System.out.println("通讯关闭失败~");
                    }

            }
        }
    }
}

































